Energy storage, such as in supercapacitors, is important in order to improve energy efficiency. Additionally, carbon dioxide capture is becoming important in order to reduce the quantity of greenhouse gases in the atmosphere. Nano-carbon foams can be used as electrodes in supercapacitors, and they can also be used to capture carbon dioxide. However, existing methods of preparing nano-carbon foam are not suitable for large scale industrial production. For example, chemical solution-based methods often require a significant number of pre- and post-processing steps, and they result in the generation of chemical waste. Therefore, improved methods of making nano-carbon foams are desirable, particularly methods that are suitable for industrial scale production.